JP2008030060A - Laser beam machining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining device capable of easily and drastically changing the dimension of a beam cross section. <P>SOLUTION: A lens array system moving mechanism switches a first state in which a first lens array system is arranged at a prescribed position for a laser beam to enter, and a second state in which a second lens array system is arranged at a prescribed position for a laser beam to enter. The first and the second lens array system each contain a cylindrical lens array, splitting an incident laser beam into light beam bundles corresponding to each cylindrical lens. In the first state, the light beam bundle split by the first lens array system is superimposed by a condensing lens on the same area on a surface to be machined, with the beam cross section of the first dimension formed. In the second state, the light beam bundle split by the second lens array system is superimposed by the condensing lens on the same area on the surface to be machined, with the beam cross section of the second dimension formed that is different from the first dimension. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laser processing apparatus, and more particularly to a laser processing apparatus having an optical system for shaping a cross section of a laser beam.

  A cylindrical lens array is used to divide a laser beam into a plurality of beam bundles, and the divided beam bundles are overlapped by a condensing lens to shape the beam cross section and make the light intensity distribution in the beam cross section uniform. A homogenizer to be used is used in a laser processing apparatus (see, for example, Patent Document 1).

  For example, a laser beam having a beam cross section elongated in one direction can be generated by the homogenizer. Such a laser beam is used for, for example, laser annealing for polycrystallizing an amorphous silicon film with a laser beam. The silicon film in the region scanned by the laser beam is polycrystallized by scanning the laser beam in a direction perpendicular to the length direction of the beam cross section on the processing surface on which the amorphous silicon film is formed. Can do.

  For example, there is a case where it is desired to change the length of the cross section of the laser beam used for laser annealing according to the size of the workpiece. In such a case, the length of the beam cross section on the processing surface can be changed to some extent by changing the position of the cylindrical lens array of the homogenizer from the reference position with respect to the traveling direction of the laser beam.

  For example, in a homogenizer in which a beam cross section having a length of 100 mm can be obtained by a cylindrical lens array arranged at a reference position, a length of about 80 to 120 mm is obtained by moving the cylindrical lens array with respect to the traveling direction of the laser beam. A beam cross section can be obtained.

JP 2002-025933 A

  With the technique described above, the length of the beam cross section cannot be changed significantly. For example, it is difficult to obtain a beam cross section having a length of 50 mm with a homogenizer in which a beam cross section having a length of 100 mm is obtained by a cylindrical lens array arranged at the reference position.

  In addition, the light intensity distribution in the beam cross section on the processing surface deviates from a desired one by changing the length of the beam cross section by moving the cylindrical lens array from the reference position with respect to the traveling direction of the laser beam. The problem also arises.

  An object of the present invention is to provide a laser processing apparatus capable of easily and greatly changing the dimension of a beam cross section.

  Another object of the present invention is to provide a laser processing apparatus having a novel optical system for shaping a beam cross section.

  According to the first aspect of the present invention, a laser light source that emits a laser beam, and a first direction that intersects with a traveling direction of the incident laser beam when the laser beam is incident at the first position. A first lens array system that includes at least one lens array including a plurality of cylindrical lenses arranged in parallel to each other and divides the incident laser beam into a plurality of light bundles corresponding to the respective cylindrical lenses of the lens array; The laser beam is incident when arranged at the second position and includes at least one column of a lens array including a plurality of cylindrical lenses arranged in a direction parallel to the first direction, and the incident laser beam is a lens. A second lens array system that divides into a plurality of light bundles corresponding to each cylindrical lens of the array, and the first lens array; Is disposed at the first position, and the second lens array system is retracted to a position where no laser beam is incident, and the second lens array system is disposed at the second position. And the first lens array system for moving the first and second lens array systems so as to switch between the second state in which the first lens array system is retracted to a position where the laser beam is not incident. A plurality of light beams that have a moving mechanism, a condensing lens, and a holding table for holding a workpiece on which a laser beam is incident, and are divided by the first lens array system in the first state The bundle is incident on the condenser lens, and the condenser lens has the same range with respect to the direction corresponding to the first direction on the surface of the object to be processed held by the holding table. Of the workpiece A cross section of the beam having a first dimension with respect to the direction on the surface is generated, and in the second state, a plurality of light bundles divided by the second lens array system are incident on the condenser lens; The condensing lens superimposes a plurality of incident light bundles on the surface of the processing object on the surface of the processing object held on the holding table in the same range with respect to the direction corresponding to the first direction. A laser processing apparatus for generating a beam cross section having a dimension different from the first dimension with respect to the direction is provided.

According to the second aspect of the present invention, the laser light source that emits the laser beam and the laser light source arranged in the first position and arranged in a direction parallel to the first direction intersecting the traveling direction of the incident laser beam. A first lens array system including at least one column of a lens array including a plurality of cylindrical lenses, and dividing the incident laser beam into a plurality of light bundles corresponding to the respective cylindrical lenses of the lens array; and a second lens array system. , Including at least one column of a lens array including a plurality of cylindrical lenses arranged in a direction parallel to the first direction, and dividing an incident laser beam into a plurality of light bundles corresponding to the respective cylindrical lenses of the lens array. The second lens array system and the second lens array, and directing the laser beam to be incident on the first lens array system. A first state in which no laser beam is incident on the system, and a second state in which the laser beam is guided so as to be incident on the second lens array system and the laser beam is not incident on the first lens array system. An optical path switching optical system for switching between states, a condensing lens, and a holding base for holding a workpiece to which a laser beam is incident. In the first state, the first lens array system includes: A plurality of divided beam bundles enter the condenser lens, and the condenser lens corresponds to the first direction on the surface of the workpiece to be processed held by the holding table. A beam cross section having a first dimension with respect to the direction is generated on the surface of the workpiece to be overlapped in the same range with respect to the direction to be processed, and is divided by the second lens array system in the second state. A plurality of light bundles The light is incident on the lens, and the condensing lens superimposes the incident light bundles on the surface of the object to be processed held on the holding table in the same range with respect to the direction corresponding to the first direction, There is provided a laser processing apparatus for generating a beam cross section having a dimension different from the first dimension with respect to the direction on the surface of an object to be processed.

  In the laser processing apparatus according to the first aspect, the first lens array moving mechanism switches between the first state and the second state. Thereby, on the surface to be processed, the beam cross section having a dimension corresponding to the first state and the beam cross section having a dimension corresponding to the second state can be switched.

  In the laser processing apparatus according to the second aspect, the optical path switching optical system switches between the first state and the second state. Thereby, on the surface to be processed, the beam cross section having a dimension corresponding to the first state and the beam cross section having a dimension corresponding to the second state can be switched.

  A laser processing apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a schematic diagram of the laser processing apparatus of the first embodiment. The laser light source 1 emits a laser beam. The laser light source 1 emits, for example, a second harmonic of an Nd: YAG laser. A laser beam emitted from the laser light source 1 enters the homogenizer optical system 3 through the zoom optical system 2. The zoom optical system 2 can make the cross section of the laser beam incident on the homogenizer optical system 3 a desired size.

  The homogenizer optical system 3 includes a short lens array system 11, a first long lens array system 12, a second long lens array system 13, a condenser lens 21, a first linear stage mechanism 32, and a first linear stage mechanism 32. 2 linear stage mechanisms 33 are included. The control device 100 controls the first and second linear stage mechanisms 32 and 33.

  The first linear stage mechanism 32 holds the first long lens array system 12 so as to be movable in a direction orthogonal to the traveling direction of the incident laser beam. The second linear stage mechanism 33 holds the second long lens array system 13 so as to be movable in a direction orthogonal to the traveling direction of the incident laser beam.

  In the homogenizer optical system 3, the first long lens array system 12 is arranged on the optical path of the laser beam by the first linear stage mechanism 32, and the second long lens array system 13 is connected to the second long lens array system 13. The linear stage mechanism 33 is used in the first state retracted to a position where the laser beam is not incident, or the second long lens array system 13 is used by the second linear stage mechanism 33 for the light of the laser beam. The first long lens array system 12 disposed on the road is used in the second state where it is retracted to a position where the laser beam is not incident by the first linear stage mechanism 32. FIG. 1A shows the homogenizer optical system 3 set in the first state.

  The laser beam that has passed through the homogenizer optical system 3 enters the workpiece 4. The homogenizer optical system 3 shapes the beam cross section into an elongated shape in one direction on the surface of the workpiece 4 (on the surface to be processed), and makes the light intensity distribution in the beam cross section uniform. The length of the beam cross section on the processing surface when the homogenizer optical system 3 is set to the first state is, for example, 50 mm, and the beam cross section on the processing surface when the homogenizer optical system 3 is set to the second state. The length of is, for example, 100 mm. The width of the beam cross section on the processing surface is, for example, 50 μm in both the first and second states.

  The workpiece 4 is, for example, a glass substrate having an amorphous silicon film formed on the surface. The XY stage 5 holds the workpiece 4. The XY stage 5 can move the workpiece 4 within a plane parallel to the workpiece surface. By scanning a laser beam whose cross section is shaped to be elongated in one direction on the processing surface in the width direction of the beam cross section, the silicon film in the scanned region can be polycrystallized.

  Next, with reference to FIG. 1 (B), FIG. 1 (C), and FIG. 2, the optical system which the 1st elongate lens array system 12 and the condensing lens 21 comprise in a 1st state is demonstrated. To do. Here, an XYZ orthogonal coordinate system having a Z axis parallel to the traveling direction of the laser beam incident on the homogenizer optical system 3 is defined. The direction in which the laser beam travels is taken as the positive Z-axis direction. FIG. 1 (B) shows the first long lens array system 12 and the condenser lens 21 as seen with a line of sight parallel to the X axis direction, and FIG. 1 (C) shows a line of sight parallel to the Y axis direction. The first long lens array system 12 and the condenser lens 21 as seen are shown.

  The first long lens array system 12 includes two columns of cylindrical lens arrays 121 and 122 arranged at a predetermined interval in the Z-axis direction. Each of the cylindrical lens arrays 121 and 122 includes a plurality of cylindrical lenses that are held in a posture in which the generatrix direction is parallel to the X-axis direction and are aligned in a direction parallel to the Y-axis direction. Both cylindrical lens arrays 121 and 122 have the same number of cylindrical lenses.

  The plurality of cylindrical lenses constituting the cylindrical lens array 121 have the same shape, and the plurality of cylindrical lenses constituting the cylindrical lens array 122 have the same shape. The widths of the cylindrical lenses in the cylindrical lens arrays 121 and 122 in the Y-axis direction are equal. Note that the cylindrical lens of the cylindrical lens array 121 and the cylindrical lens of the cylindrical lens array 122 are not necessarily in the same shape.

  Cylindrical lens arrays 121 and 122 are arranged so that the centers in the Y-axis direction of the cylindrical lenses arranged in the positive direction from the negative direction of the Y-axis coincide with each other.

  The laser beam is incident on the cylindrical lens array 121. The light intensity distribution Dy in the Y-axis direction in the cross section of the laser beam incident on the cylindrical lens array 121 is relatively high at the central portion of the beam cross section and relatively low at the peripheral portion, and sandwiches the center of the beam cross section. Almost symmetrical with respect to the Y-axis direction.

  In the first state, the incident laser beam and the first long lens array system 12 are arranged such that the center of the cross section of the incident laser beam in the Y axis direction passes through the center of the cylindrical lens array 121 in the Y axis direction. Relative position is set.

  The laser beam incident on the cylindrical lens array 121 is divided into a number of beam bundles corresponding to each cylindrical lens of the cylindrical lens array 121 in the Y-axis direction. Each light bundle divided by the cylindrical lens array 121 is transmitted through each corresponding cylindrical lens of the cylindrical lens array 122. As shown in FIG. 1C, in the X-axis direction, the cylindrical lens arrays 121 and 122 are equivalent to simple transparent flat plates.

  In the first state, the laser beam that has passed through the first long lens array system 12 passes through the condenser lens 21 and enters the workpiece 4. The condensing lens 21 superimposes a plurality of light bundles divided in the Y-axis direction by the first long lens array system 12 on the processing surface in the same range in the Y-axis direction. As a result, a beam cross section having a predetermined dimension in the Y-axis direction on the processing surface can be obtained.

  Consider a pair of cylindrical lenses disposed at equal distances from the center of the cylindrical lens array 121 in the Y-axis direction. The light intensity distributions in the Y-axis direction of the two light bundles that have passed through each of these two cylindrical lenses have a tendency to increase or decrease opposite to each other. Therefore, in the light in which these two light bundles are overlapped in the same range in the Y-axis direction, the light intensity distribution in the Y-axis direction approaches uniformly.

  All the pairs of ray bundles whose light intensity distributions in the Y-axis direction tend to increase or decrease opposite to each other are superimposed on the same range by the condenser lens 21. In this way, a laser beam can be obtained in which the light intensity distribution in the cross section in the Y-axis direction is made close to uniform on the surface to be processed.

  Furthermore, with reference to FIG. 2, the optical system which the 1st elongate lens array system 12 and the condensing lens 21 comprise in a 1st state is demonstrated. The upper diagram in FIG. 2 shows the first long lens array system 12 and the condenser lens 21 as viewed from a line of sight parallel to the X-axis direction. In FIG. 2, one set of lens arrays of the first long lens array system 12 is shown as a representative.

  The focal length of the first long lens array system 12 is fa1, and the focal length of the condenser lens 21 is fc. The focal length fc of the condenser lens 21 is longer than the focal length fa1 of the first long lens array system 12. The first long lens array system 12 and the condenser lens 21 constitute a magnifying optical system having a magnification fc / fa1 with respect to the Y-axis direction. Assuming that the width of each cylindrical lens constituting the first long lens array system 12 in the Y-axis direction is hy1, a beam cross section having a length obtained by multiplying the width hy1 of the cylindrical lens by fc / fa1 is formed on the processing surface. Is generated.

  Next, referring back to FIG. 1, the optical system constituted by the second long lens array system 13 and the condenser lens 21 in the second state will be described. The second long lens array system 13 is composed of two rows of cylindrical lens arrays 131 and 132 arranged at a predetermined interval in the Z-axis direction.

  The cylindrical lens arrays 131 and 132 have different focal lengths from the cylindrical lens arrays 121 and 122 constituting the first long lens array system 12. With respect to the Z-axis direction, the interval from the cylindrical lens arrays 131 to 132 is different from the interval from the cylindrical lens arrays 121 to 122 of the first long lens array system 12. Other than that, the second long lens array system 13 has the same configuration as that of the first long lens array system 12.

  In the second state, the incident laser beam and the second long lens array system 13 are arranged such that the center of the cross section of the incident laser beam in the Y axis direction passes through the center of the cylindrical lens array 131 in the Y axis direction. Relative position is set.

  In the second state, a plurality of light bundles divided in the Y-axis direction by the second long lens array system 13 are superimposed on the processing surface by the condenser lens 21 in the same range in the Y-axis direction. Thus, a beam cross section having a predetermined dimension in the Y-axis direction on the surface to be processed and in which the light intensity distribution is made close to uniform is obtained.

  Furthermore, with reference to FIG. 2, the optical system which the 2nd elongate lens array system 13 and the condensing lens 21 comprise in a 2nd state is demonstrated. The lower diagram of FIG. 2 shows the second long lens array system 13 and the condenser lens 21 as viewed from a line of sight parallel to the X-axis direction. In FIG. 2, one set of lens arrays of the second long lens array system 13 is shown as a representative.

  The focal length of the second long lens array system 13 is fa2. The focal length fa2 of the second long lens array system 13 is shorter than the focal length fa1 of the first long lens array system 12. Further, the focal length fc of the condenser lens 21 is longer than the focal length fa2 of the second long lens array system 13.

  The second long lens array system 13 and the condenser lens 21 constitute a magnifying optical system having a magnification fc / fa2 in the Y-axis direction. Assuming that the width in the Y-axis direction of each cylindrical lens constituting the second long lens array system 13 is hy2, the beam cross section having a length obtained by multiplying the width hy2 of the cylindrical lens by fc / fa2 is on the surface to be processed. Is generated.

  Assume that the widths hy1 and hy2 of the cylindrical lenses of the first and second long lens array systems 12 and 13 are equal. For example, considering the case where the focal length fa2 of the second long lens array system 13 is ½ of the focal length fa1 of the first long lens array system 12, the magnification in the second state fc / fa2 is twice the magnification fc / fa1 in the first state. That is, in such a case, the length of the beam cross section generated in the second state is twice that of the first state. In this way, by switching between the first state and the second state, the dimension of the beam cross section on the processing surface in the Y-axis direction can be switched.

  Next, referring to FIG. 1 again, the optical system constituted by the short lens array system 11 and the condenser lens 21 will be described. The short lens array system 11 has a configuration in which one long lens array system is rotated 90 degrees in a plane parallel to the XY plane. The short lens array system 11 is composed of two columns of cylindrical lens arrays 111 and 112 arranged at a predetermined interval in the Z-axis direction. The cylindrical lens arrays 111 and 112 each have a generatrix direction parallel to the Y-axis direction. Thus, it is composed of a plurality of cylindrical lenses arranged in the X-axis direction. The short lens array system 11 divides the incident laser beam into a plurality of beam bundles in the X-axis direction.

  A plurality of light bundles divided in the X-axis direction by the short lens array system 11 are superimposed on the processing surface by the condensing lens 21 in the same range in the X-axis direction, and the X-axis direction on the processing surface. As a result, a beam cross section having a predetermined dimension and a light intensity distribution close to uniform can be obtained.

  However, the focal length fb of the short lens array system 11 is longer than the focal length fc of the condenser lens 21. The short lens array system 11 and the condenser lens 21 constitute a reduction optical system having a magnification fc / fb with respect to the X-axis direction. Assuming that the width in the X-axis direction of each cylindrical lens constituting the short lens array system 11 is hx, a beam cross section having a width obtained by multiplying the width hx of the cylindrical lens by fc / fb is generated on the processing surface.

  Next, the first linear stage mechanism 32, the second linear stage mechanism 33, and the cylindrical lens array holding mechanism will be described with reference to FIGS. 3 (A) and 3 (B).

  FIG. 3A shows the first and second linear stage mechanisms 32 and 33 viewed from a line of sight parallel to the X-axis direction, and the first and second long lens array systems 12 held by them respectively. And 13 are schematically shown.

  The first linear stage mechanism 32 includes a linear guide 321 including a moving table 322 and a drive mechanism 323. The drive mechanism 323 moves the moving base 322 along the rail of the linear guide 321 in the Y axis direction.

  Lens holding mechanisms 41 and 42 hold the cylindrical lens arrays 121 and 122, respectively. Lens holding mechanisms 41 and 42 are attached to a moving table 322 of the first linear stage mechanism 32. By moving the moving table 322, the cylindrical lens arrays 121 and 122 of the first long lens array system 12 can be moved in the Y-axis direction.

  The second linear stage mechanism 33 also has the same configuration as the first linear stage mechanism 32. Cylindrical lens arrays 131 and 132 of the second long lens array system 13 are held by lens holding mechanisms 43 and 44, respectively. The lens holding mechanisms 43 and 44 are movable bases 332 of the second linear stage mechanism 33. Is attached. By moving the moving table 332, the cylindrical lens arrays 131 and 132 of the second long lens array system 13 can be moved in the Y-axis direction.

  FIG. 3B schematically shows the first linear stage mechanism 32 and the lens holding mechanism 41 attached to the first linear stage mechanism 32 as viewed in a line of sight parallel to the Z-axis direction. The lens holding mechanism 41 includes a lens holding frame 411, a lens holding frame holding member 412, a base 413, a rotation direction fine movement mechanism 414, and a long direction fine movement mechanism 415.

  A cylindrical lens array 121 is fitted in the frame of the lens holding frame 411. A lens holding frame holding member 412 holds the lens holding frame 411. A support shaft 416 is attached to the lens holding frame holding member 412, and the lens holding frame 411 can be displaced in the rotational direction around the support shaft 416 in a plane parallel to the XY plane. The rotation direction fine movement mechanism 414 can finely adjust the generatrix direction of the cylindrical lenses constituting the cylindrical lens array 121 by displacing the lens holding frame 411 by a minute angle in the rotation direction from the reference position in the rotation direction.

  The base 413 holds the lens holding frame holding member 412 so as to be movable in a direction parallel to the Y-axis direction. The longitudinal fine movement mechanism 415 finely moves the lens holding frame holding member 412 with respect to the base 413 from the reference position in the Y-axis direction with respect to the Y-axis direction, thereby changing the incident position of the laser beam on the cylindrical lens array 121. , Fine adjustment can be made with respect to the Y-axis direction. For example, a micrometer mechanism is used as the long direction fine movement mechanism 415. The stroke of the longitudinal fine movement mechanism 415 is, for example, about 5 mm.

  A base 413 of the lens holding mechanism 41 is attached to the moving base 322 of the first linear stage mechanism 32. The dimension of the cylindrical lens array 121 in the Y-axis direction is, for example, about several cm to 10 cm, and the stroke of the first linear stage mechanism 32 is, for example, about 10 cm to 20 cm. The weight of the cylindrical lens array 121 is, for example, about 1 kg to 2 kg.

  When the first linear stage mechanism 32 moves the cylindrical lens array 121 to the left in the drawing (in the positive Y-axis direction), the cylindrical lens array 121 is retracted to a position where the laser beam is not incident.

  When the first linear stage mechanism 32 moves the cylindrical lens array 121 to the right (in the negative Y-axis direction) to a desired position, the right edge of the moving table 322 of the first linear stage mechanism 32 is In contact with the set screw 324 whose relative position is fixed with respect to the linear guide 321, the moving base 322 does not move rightward any further. In this way, the cylindrical lens array 121 is positioned at a desired position.

  After the cylindrical lens array 121 is positioned by the first linear stage mechanism 32, the cylindrical fine array mechanism 415 and the long direction fine movement mechanism 415 included in the lens holding mechanism 41 are used as necessary, as described above. The posture of the lens array 121 is finely adjusted. Once fine adjustment is completed, there is no need to make fine adjustment again even if the first state and the second state are switched.

  The other cylindrical lens arrays 122, 131 and 132 are also held by a lens holding mechanism having the same configuration as that of the cylindrical lens array 121, and the base of each lens holding mechanism is attached to the moving stage of the linear stage mechanism. It is done.

  If the laser processing apparatus according to the embodiment described above is used, the first and second linear stage mechanisms are used to switch between the first state and the second state, thereby generating two types of beam cross sections. Can do. It is also easy to change the length of the beam cross section significantly (for example, from 100 mm to 50 mm).

  For example, by switching the state of the homogenizer optical system 3 in accordance with the type of the processing object determined by the dimensions of the processing object, it is possible to perform processing by switching the length of the beam cross section on the processing surface.

  A region on the processing surface on which the laser beam is incident in one scan is referred to as a unit region. A unit region to be scanned with a laser beam having a first length beam cross section and a unit region to be scanned with a laser beam having a second length beam cross section are defined on one workpiece. Think about the case. In such a case, by switching the state of the homogenizer optical system 3 according to the unit area, it is possible to perform processing by switching the length of the beam cross section on the processing surface.

  Since the long lens array system does not move with respect to the traveling direction of the laser beam, there is no problem that the light intensity distribution in the beam cross section deteriorates with such movement.

  Next, with reference to FIG. 4, a laser processing apparatus according to the second embodiment will be described. In the first embodiment, the first and second long lens array systems 12 and 13 are moved by the first and second linear stage mechanisms 32 and 33, respectively. However, in the second embodiment, Instead of the first and second linear stage mechanisms 32 and 33, one linear stage mechanism 32a is used.

  First and second long lens array systems 12 and 13 are mounted side by side with respect to the Y-axis direction, which is the moving direction of the moving table 32a2, on the moving table 32a2 of the linear stage mechanism 32a. In the first state, the first long lens array system 12 is disposed at a predetermined position on the optical path of the laser beam, and the second long lens array system 13 is retracted to a position where the laser beam is not incident. Thus, in the second state, the second long lens array system 13 is disposed at a predetermined position on the optical path of the laser beam, and the first long lens array system 12 is not incident on the laser beam. The first and second long lens array systems 12 and 13 are arranged on the movable table 32a2 so as to be retracted to the position.

  Furthermore, when it is desired to obtain a beam cross section having a length different from that obtained in the first and second states, the third long lens array system 14 can be arranged on the moving table 32a2. When any one of the first to third long lens array systems 12 to 14 is used (arranged on the optical path of the laser beam), the other two long lens array systems are laser beams. The first to third long lens array systems 12 to 14 are arranged on the moving table 32a2 so as to be retracted to a position where no light enters. If necessary, four or more long lens array systems can be used.

  Of the three or more long lens array systems arranged on the moving table, those other than those arranged at both ends in the Y-axis direction cannot be positioned by the set screw, so that the position is sufficiently high. It is necessary to use a linear stage mechanism having accuracy.

  In the laser processing apparatus of the second embodiment, the number of linear stage mechanisms can be reduced as compared with the laser processing apparatus of the first embodiment. In the laser processing apparatus of the first embodiment, when it is desired to obtain a beam cross section having a length different from that obtained in the first and second states, a third long lens array system is further provided. Can be added. A linear stage mechanism for moving the third long lens array system is also added.

  Next, with reference to FIG. 5, the laser processing apparatus of the 3rd Example is demonstrated. Although this embodiment also has two long lens array systems, the configuration of the long lens array system is different from that of the first embodiment.

  FIG. 5 shows the first and second linear stage mechanisms 32b and 33b viewed from a line of sight parallel to the X-axis direction, and the first and second long lens array systems 12b and 13b held by them respectively. Shown schematically.

  Two rows of cylindrical lens arrays 12b1 and 12b2 constitute a first long lens array system 12b, and two rows of cylindrical lens arrays 13b1 and 13b2 constitute a second long lens array system 13b. Of the optical path of the laser beam, the laser light source side is referred to as upstream, and the workpiece side is referred to as downstream. With respect to the Z-axis direction, between the cylindrical lens arrays 12b1 and 12b2 constituting the first long lens array system 12b, the upstream side of the cylindrical lens array constituting the second long lens array system 13b. A cylindrical lens array 13b1 is disposed.

  In the first embodiment, among the cylindrical lens arrays constituting the first long lens array system 12, the second long lens array system 13 is arranged more than the cylindrical lens array 122 arranged on the most downstream side. Among the cylindrical lens arrays to be configured, the cylindrical lens array 131 arranged on the most upstream side is arranged on the downstream side. That is, a cylindrical lens array constituting another long lens array system is not disposed between a plurality of columns of cylindrical lens arrays constituting a long lens array system.

  Depending on the design of the optical system, in the Z-axis direction, as in the third embodiment, another long lens array system may be provided between a plurality of cylindrical lens arrays constituting a long lens array system. A cylindrical lens array to be configured may be arranged.

  A holding table 52 is attached to the moving table 32b2 of the first linear stage mechanism 32b, and the holding table 52 holds the cylindrical lens arrays 12b1 and 12b2 constituting the first long lens array system 12b. The holding base 52 holds the cylindrical lens arrays 12b1 and 12b2 so as to be arranged at a predetermined interval with respect to the Z-axis direction.

  Further, a holding table 53 is attached to the moving table 33b2 of the second linear stage mechanism 33b, and the holding table 53 holds the cylindrical lens arrays 13b1 and 13b2 constituting the second long lens array system 13b. The holding base 53 holds the cylindrical lens arrays 13b1 and 13b2 so as to be arranged at a predetermined interval with respect to the Z-axis direction.

  Cylindrical lens arrays 12b1 and 12b2 constituting the first long lens array system 12b are brought closer to the optical path LB of the laser beam from the Y-axis negative direction side and retracted toward the Y-axis negative direction side. The cylindrical lens arrays 13b1 and 13b2 constituting the second long lens array system 13b are brought closer to the optical path LB of the laser beam from the Y axis positive direction side and retracted toward the Y axis positive direction side. With such a configuration, for example, the holding bases 52 and 53 can hardly interfere with each other.

  A configuration in which the cylindrical lens arrays 12b1, 12b2, 13b1, and 13b2 are all moved by separate linear stage mechanisms is also possible. However, since the plurality of cylindrical lens arrays constituting one long lens array system act as one set of lenses, as in the third embodiment, a plurality of cylindrical lens arrays constituting one long lens array system are arranged. It is preferable that the cylindrical lens arrays are held by a common linear stage mechanism and moved while the relative positional relationship between the cylindrical lens arrays is fixed. The apparatuses of the first and second embodiments also hold the cylindrical lens array constituting one long lens array system in a common linear stage mechanism.

  Next, a laser processing apparatus according to a fourth embodiment will be described with reference to FIG. In this embodiment, the long lens array system is moved by a rotary stage mechanism instead of the linear stage mechanism. FIG. 6 schematically shows the rotary stage mechanism 61 viewed from a line of sight parallel to the Z-axis direction, and the first and second long lens array systems 12 and 13 held therein.

  A first long lens array system 12 is attached to the rotary stage mechanism 61 via a holding table 72, and a second long lens array system 13 is attached via a holding table 73. The rotary stage mechanism 61 rotates the first and second long lens array systems 12 and 13 around an axis parallel to the Z-axis direction.

  In the first state, the first long lens array system 12 is disposed at a predetermined position on the optical path of the laser beam, and the second long lens array system 13 is retracted to a position where the laser beam is not incident. Thus, in the second state, the second long lens array system 13 is disposed at a predetermined position on the optical path of the laser beam, and the first long lens array system 12 is not incident on the laser beam. Both long lens array systems are attached to the rotary stage mechanism 61 so as to be retracted to the position.

  Next, a laser processing apparatus according to the fifth embodiment will be described with reference to FIG. In this embodiment, in order to switch the width of the beam cross section, two types of short lens array systems are prepared in the homogenizing optical system. The first short lens array system 10d and the second short lens array system 11d are arranged at a predetermined interval in the Z-axis direction.

  The third linear stage mechanism 30d moves the first short lens array system 10d in a direction orthogonal to the traveling direction of the laser beam incident on the first short lens array system 10d. The fourth linear stage mechanism 31d moves the second short lens array system 11d in a direction orthogonal to the traveling direction of the laser beam incident on the second short lens array system 11d.

  As in the case of switching the length of the beam cross section, the first short lens array system 10d is disposed at a predetermined position on the optical path of the laser beam, and the second short lens array system 11d is not incident on the laser beam. The second short lens array system 11d is disposed at a predetermined position on the optical path of the laser beam, and the first short lens array system 10d is retracted to a position where the laser beam is not incident. Can be switched to change the width of the beam cross section on the surface to be processed.

  In the above embodiment, one long lens array system is composed of a plurality of columns of cylindrical lens arrays. However, one long lens array system can be composed of a single column of cylindrical lens arrays. is there. The same applies to the short lens array system.

  Next, a laser processing apparatus according to the sixth embodiment will be described with reference to FIG. In this embodiment, instead of moving the long lens array system, the length of the beam cross section is switched by allocating the laser beam to a plurality of long lens array systems arranged at predetermined positions.

  The laser beam emitted from the laser light source 1e enters the short lens array 11e via the zoom optical system 2e. A first partial optical system 811 of the optical path switching optical system 81 is disposed downstream of the short lens array system 11e.

  The first partial optical system 811 includes a first optical path where the laser beam is incident on the first long lens array system 12e, and a second optical path where the laser beam is incident on the second long lens array system 13e. Switch between optical paths.

  A second partial optical system 812 is disposed downstream of the first and second long lens array systems 12e and 13e. The second partial optical system 812 causes the laser beam that has passed through the first long lens array system 12e or the laser beam that has passed through the second long lens array system 13e to enter the condensing lens 21e. . The control device 100e controls the optical path switching optical system 81.

  The homogenizer optical system 3e includes a short lens array system 11e, a first long lens array system 12e, a second long lens array system 13e, a condenser lens 21e, and an optical path switching optical system 81. Is done. The laser beam that has passed through the homogenizer optical system 3e is incident on the workpiece 4e held on the XY stage 5e.

  When the laser beam passes through the first optical path, the optical system constituted by the first long lens array system 12e and the condenser lens 21e shapes the beam cross section on the processing surface to a desired first length. To do. When the laser beam passes through the second optical path, the optical system constituted by the second long lens array system 13e and the condenser lens 21e shapes the beam cross section on the processing surface into a desired second length. To do.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

FIG. 1A is a schematic diagram of the laser processing apparatus according to the first embodiment, and FIGS. 1B and 1C show an optical system comprising a long lens array system and a condenser lens. FIG. FIG. 2 is a diagram showing the arrangement of the first and second long lens array systems, the condensing lens, and the processing object. 3A and 3B are schematic views of the linear stage mechanism and the lens holding mechanism. FIG. 4 is a schematic view of a linear stage mechanism included in the laser processing apparatus according to the second embodiment. FIG. 5 is a diagram showing a configuration of a long lens array system and a linear stage mechanism included in the laser processing apparatus according to the third embodiment. FIG. 6 is a schematic view of a rotary stage mechanism included in the laser processing apparatus according to the fourth embodiment. FIG. 7 is a schematic view of a homogenizer optical system included in the laser processing apparatus according to the fifth embodiment. FIG. 8 is a schematic view of a laser processing apparatus according to the sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser light source 2 Zoom optical system 3 Homogenizer optical system 4 Work object 5 XY stage 11 Short lens array system 12, 13 Long lens array system 111, 112, 121, 122, 131, 132 Cylindrical lens arrays 32, 33 Linear stage mechanism 100 control device

Claims (7)

A laser light source for emitting a laser beam;
When arranged at the first position, the laser beam is incident, and at least one lens array comprising a plurality of cylindrical lenses arranged in a direction parallel to the first direction intersecting the traveling direction of the incident laser beam. A first lens array system that divides the incident laser beam into a plurality of beam bundles corresponding to each cylindrical lens of the lens array;
The laser beam is incident when arranged at the second position and includes at least one lens array including a plurality of cylindrical lenses arranged in a direction parallel to the first direction, and the incident laser beam is a lens array. A second lens array system that divides into a plurality of light bundles corresponding to each of the cylindrical lenses;
A first state in which the first lens array system is disposed at the first position and the second lens array system is retracted to a position where no laser beam is incident; and the second lens array system is The first and second lens array systems are moved so as to switch between the second state that is disposed at the second position and the first lens array system is retracted to a position where the laser beam is not incident. A first lens array system moving mechanism
A condenser lens;
A holding table for holding the workpiece on which the laser beam is incident;
In the first state, a plurality of light bundles divided by the first lens array system are incident on the condenser lens, and the condenser lens holds the plurality of incident light bundles on the holding table. Generating a beam cross section having a first dimension with respect to the direction on the surface of the workpiece, overlapping the same range with respect to the direction corresponding to the first direction on the surface of the workpiece.
In the second state, a plurality of light bundles divided by the second lens array system enter the condenser lens, and the condenser lens holds the plurality of incident light bundles on the holding table. A beam cross-section having a dimension different from the first dimension with respect to the direction on the surface of the workpiece is generated by overlapping the same range with respect to the direction corresponding to the first direction on the surface of the workpiece. Laser processing equipment.   At least one of the first and second lens array systems includes a plurality of rows of lens arrays arranged in the traveling direction of an incident laser beam, and the first lens array system moving mechanism includes a lens array system. The laser processing apparatus according to claim 1, wherein the lens array system is moved while fixing a relative positional relationship between a plurality of lens arrays. further,
A first holding member for holding a lens array included in the first lens array system;
A second holding member movably holding the first holding member;
A fine movement mechanism for finely moving the first holding member with respect to a direction in which the lenses of the lens array held by the first holding member are arranged with respect to the second holding member; The laser processing apparatus according to claim 1, wherein the array system moving mechanism moves the first lens array system by moving the second holding member. further,
When arranged at the third position, the laser beam is incident, and includes a plurality of cylindrical lenses arranged in a direction parallel to a traveling direction of the incident laser beam and a second direction intersecting the first direction. A third lens array system including at least one row of lens arrays and dividing an incident laser beam into a plurality of light bundles corresponding to the respective cylindrical lenses of the lens array;
The laser beam is incident when arranged at the fourth position and includes at least one lens array including a plurality of cylindrical lenses arranged in a direction parallel to the second direction. The incident laser beam is a lens array. A fourth lens array system that divides into a plurality of light bundles corresponding to each of the cylindrical lenses;
A third state in which the third lens array system is disposed at the third position and the fourth lens array system is retracted to a position where no laser beam is incident; and the fourth lens array system is The third and fourth lens array systems are moved so as to switch between the fourth state, which is disposed at the fourth position and the third lens array system is retracted to a position where the laser beam is not incident. A second lens array system moving mechanism
In the third state, a plurality of light bundles divided by the third lens array system enter the condenser lens, and the condenser lens holds the incident light bundles on the holding table. Generating a beam cross section having a second dimension with respect to a direction corresponding to the second direction on the surface of the workpiece to be overlapped in the same range with respect to the direction corresponding to the second direction;
In the fourth state, a plurality of light bundles divided by the fourth lens array system enter the condenser lens, and the condenser lens holds the incident light bundles on the holding table. A beam cross section having a dimension different from the second dimension with respect to the direction on the surface of the workpiece is generated by overlapping the same range with respect to the direction corresponding to the second direction on the surface of the workpiece. The laser processing apparatus according to any one of claims 1 to 3.   The processing object is further classified into a plurality of types, and a control device that controls the first lens array system moving mechanism based on the type of the processing object is provided. The laser processing apparatus as described in.   Further, a plurality of unit regions to be processed are defined on the surface of the processing object, and a control device for controlling the first lens array system moving mechanism is provided for each unit region. The laser processing apparatus of Claim 1. A laser light source for emitting a laser beam;
A lens array including a plurality of cylindrical lenses arranged at a first position and arranged in a direction parallel to a first direction intersecting a traveling direction of an incident laser beam, the incident laser beam being a lens; A first lens array system that divides into a plurality of light bundles corresponding to each cylindrical lens of the array;
A plurality of lens arrays each including a plurality of cylindrical lenses arranged at a second position and arranged in a direction parallel to the first direction, and a plurality of incident laser beams corresponding to the respective cylindrical lenses of the lens array. A second lens array system that divides the beam bundle of
A first state in which a laser beam is guided so as to be incident on the first lens array system, and no laser beam is incident on the second lens array system, and is incident on the second lens array system An optical path switching optical system for guiding a laser beam and switching between a second state in which the laser beam is not incident on the first lens array system;
A condenser lens;
A holding table for holding the workpiece on which the laser beam is incident;
In the first state, a plurality of light bundles divided by the first lens array system enter the condenser lens, and the condenser lens holds the plurality of incident light bundles on the holding table. Generating a beam cross section having a first dimension with respect to the direction on the surface of the workpiece, overlapping the same range with respect to the direction corresponding to the first direction on the surface of the workpiece.
In the second state, a plurality of light bundles divided by the second lens array system enter the condenser lens, and the condenser lens holds the plurality of incident light bundles on the holding table. A beam cross-section having a dimension different from the first dimension with respect to the direction on the surface of the workpiece is generated by overlapping the same range with respect to the direction corresponding to the first direction on the surface of the workpiece. Laser processing equipment.

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